Is there something wrong?

My son will 4 this month and I’m not sure if there is a deep issue with him or not. Ever since 18 months he’s been a screamer. Over almost everything, (mad at a toy, mad he didn’t get his way, dropped something, etc.) This is his way of associating of how he’s feeling basically, we have worked and worked with him on how to express himself, how to use words. How to sit and take a breather, literally everything and nothing seems to work, hence he’s almost 4 and still is a big screamer. We have talked to his doctor, of course it doesn’t help the doctors here are in and out, but they said it’s typical, that’s how they express until they learn how to the proper way. So my question is, when the heck is that? I know every child blooms at different rates but I haven’t seen any child act the way he does at his age over everything that happens. Like he even does it on purpose because he knows it makes mommy and daddy sad and hurts our ears. I look at him and think what the heck did I do wrong?